Trippy demonstration of recursively rotating images

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“Githubber”. Celebrity coders? Why not.

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There is a subtest in the classic (early 90’s) benchmark for the X11 windowing system called x11perf which did this. I remember watching that subtest once and wondering how it worked. I think I spaced off the next half hour figuring it out in my head before I wrote a short program to do the same thing. Later, in a computer science class about tree structures, I brought it up as an example and the professor adopted it as a teaching example to use in following semesters.

If the image is viewed as a two dimensional recursive tree of blocks, then the rotation never happens–you just walk the tree in a different way and end up at different pixels. It’s a great example of ‘if you just look at it differently, you’ll see that it’s already done’.


That is a new spin on photos…

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